Ducati Monster Motorcycle Forum banner

1 - 11 of 11 Posts

·
Premium Member
Joined
·
2,952 Posts
Discussion Starter #1
As a follow on to inspecting and repacking the steering head bearings, I finally installed the set of SS adjustable Showas I had picked up a couple of months ago and went for a test ride.

The little noise gremlin didn't go away after the steering head bearing service, so I decided to swap in the "new" forks and inspect the wheel bearings while at it.

Wheel bearings still felt good, so I suspected the OEM forks may have gone south on me. (It eventually turned out that the sensation is still there - I think I just never noticed it until after logging a few miles on the BMW which is super plush feeling compared to the Monster)

Installing the adjustable Showas from a 96 900 SS turned up a couple of interesting points: The fork dimensions are pretty much the same as the non-adjustables, except that the adjusters stand a lot taller than the plain top bolts (caps). At first, I had to set the forks with the top of the tube even with the top of the triple clamp to avoid interference with the handlebars and brake/clutch hoses. That placed the center of the axle 14 mm lower from the bottom triple than the stock forks/setting. In turn, that put too much strain on the front brake lines and speedo cable when the front end was lifted clear of the floor.

By fiddling with the bars and clutch m/c, I was able to raise the forks 3.5 mm in the clamps which relieved the strain on the brake hoses and speedo cable. So now I've got the front ride height about 10 mm higher than it was. Plus, with the fork preload at the "standard" settng IAW Haynes, total sag was reduced another 5 or 6 mm from what I had with the original forks. I couldn't reduce preload any because of interference with the adjusters and handlebars.

So I went for about a 40 mile test ride where there were some of the few curvy roads around here and some washboard sections to see what effect raising the front ride height had on handling.

I was amazed to find that I actually like the turn in characterisitcs better with this setup. The forks need a little tweaking to fine tune damping over high frequency bumps and ripples, but otherwise feel a little better than the stockers.

But where the bike used to almost turn in too quickly when flicked into a turn, and especially tried to "fall" into turns around street corners at low speed - it is much steadier and easier to control with out having to correct the original steering input. Even in high speed sweepers and curves where I can get a lot of drive coming out and get the front really light it just felt better. Not as "nervous", I guess.

And no perceptible increase in effort to turn in is required. As mentioned above, it actually takes less effort on my part to complete a turn because I'm not having to correct initial steering inputs when the bike turns in too quick.

I've concluded the only other adjustment I want to make before hitting the track next Saturday is to crank in just a little more preload in the rear and increase rebound damping at the rear about 2 clicks to match the increased spring loading. That should have the two ends balanced almost as well as they were before swapping forks.

My take on all I discovered in this little exercise is that lowering the front/raising the rear to turn in quicker may be perceived as THE thing to do... But it may not be the best in every case or for all riders. If you want to check it out for yourself, try raising your front ride height about 10 mm or so. The saving grace is that it should be moving the bike toward a more stable set up rather than toward instability and possible tank slappers. YMMV.
 

·
Registered
Joined
·
3,755 Posts
I'd consider playing with that if I didn't have above-the-clamp clip-ons. I'm using all the exposed tube for the bars as it is.

Maybe when I get the cycle cats....

The great thing about raising the front AND rear is better cornering clearance!
 

·
Premium Member
Joined
·
2,952 Posts
Discussion Starter #3
Yeah, before the test ride I was sure I was going to want to raise the rear height at the suspension arch to preserve the original handling and gain some cornering clearance too.

But other than slightly increasing rear preload and rebound like I described above, I'm going to keep it as it is now for the track next weekend and get a really good opinion of the setup. I may compromise afterwards and raise the rear like half the amount of the front - 5 to 6 mm or so.

I can see an increasing likelihood of Cycle Cat clipons sometime after buying a few required maintenance items. The stock bars are just plain in the way of the adjusters and hide them from view, too. Especially since I got the BMW for long distance trips as well as dual sport riding, I'll be more prone to installing clipons for the track, spirited street riding, and looks/show off the adjustable forks, etc. I no longer feel it's as important to preserve the upright position for longer rides than say 200-250 mile days of buzzing up around Daytona or over to the Orlando area. Most of my rides on the Monster are more like 50-100 miles at a time.
 

·
Premium Member
Joined
·
743 Posts
I also first got cheaper clipons for the SBK swap and exchanged it with the CC. This mod opens up so many options it doesn't make sense to skimp and be restricted by tall, above triple clipons.
 

·
Premium Member
Joined
·
540 Posts
Hey Mark what year model do you have? I have a 2000 900 and it has higher handlebar risers than the earlier models which might help with your clearance issues. You have raised a valid point though. When I got my suspension revalved the guy who did the work (An A-grader in Aussie supersports - Glen Allerton for those Aussies here) suggested lowering the forks. I thought it would slow things down too much but he was spot on and it actually improved the turn in to make it a bit more neutral.
 

·
Premium Member
Joined
·
2,952 Posts
Discussion Starter #6
Bing,

Thanks for the corroboration. Mine is a 95 M900. It's funny, but when I let a friend ride mine (a skillful rider, but used to 600 class superbikes), he mentioned it felt like it wanted to just dive or fall into turns compared to his Kaw 636. So I know it wasn't just me feeling like I had to correct steering inputs after initiating turns.

I think I've moved in the right direction here despite most people adjusting toward quicker turning. With the OEM suspension, it was very soft, but well balanced. As a result I was getting around the same track 3 seconds quicker than on a Kaw 636 without pushing hard at all. So I feel all I need to do is dial in the back end to balance the new front forks, and with the new more stable feel I will probably get around a little faster.

Next weekend's track day is on a new track to me (Moroso), so it will be March or May before I get to compare the new setup on the track I'm familiar with (Jennings GP).

As for the risers, I have some 1/2 inch aluminum stock that I can make some spacers out of to give me another 13 mm under the bars. (I'm switching to the thumb choke lever, so no problems with the OEM style that held down by the bars).

I think in the long run I'm probably going to try clipons. With the addition of the BMW F 650 to handle long trips, the Monster is going to be mostly for day-trip type rides, so I can probably enjoy the advantages of clipons at the track and sporting around locally.
 

·
Premium Member
Joined
·
743 Posts
Mark,

I didn't see a description of actually raising both rear and front as originally planned. Did you get to try it? If so, and sorry if this is too obvious, how would you compensate on the front for the amount raised on the rear? I'm a little puzzled, since the two adjustment points are not evenly apart from the center. Looking for an easy answer at 4am...;)
 

·
Premium Member
Joined
·
2,952 Posts
Discussion Starter #9
Sivan,
I got wrapped up in replacing the throttle cable and didn't return to this thread :-[

In between a couple of 40 mile test rides on the street with the increased front ride height, the only thing I did out back was dial in 6 mm more preload on the rear spring. That reduced rear static sag by only 2 mm (I can't find where I put the loaded sag from the last adjustment to compare), but seemed to firm up the rear. I didn't touch the height adjusters.

At the track Saturday, the bike felt really good. Moroso has some of the tightest slowest chicanes you can imagine. I mean 90 degrees left at T3 flick 90 degrees right for T4. Second gear (first gear when a slower rider would get in front of me). I was able to flick it from hanging off left to hanging off right in an eyeblink and it felt stable turning. So I think I'm going to keep the current set up without any changes for now. After I take it back to Jennings, where I can compare it to a track I rode before the changes, I may raise the rear a little - more for ground clearance in corners than to compensate for the amount I raised the front. Or, maybe not. I don't want to go back to the overly quick (IMHO) steering I had before. The down side to raising the rear height is that I will have to either weld a small extension on the end of the side stand, or carry a small pad at all times to put under it so the bike doesn't fall over. The increased height already makes it lean over way farther when parked.

To answer your basic question, the only really accurate way to increase the rear height to counter the changes made by would be to actually measure the change to rake and trail as you raise or lower either end. That's not practical unless you have some high zoot measuring tools.

I took a low tech approach to calculating the changes up front. I used a protactor and scale and drew a horizontal line for the ground, a verticle reference line, and a line at 23 degrees from the ground through the reference line to represent the rake of the forks. Then by marking the changes to the fork position in the clamps to scale, I could pick off the actual change in front ride height along the vertical line. Just to get an idea of the relationship of one movement to the other, I drew a change of 10mm in fork position and measured a change in vertical height at the imaginary steering head of 9.2mm. Accurate enough for this kind of work. Since I actually lowered the forks 13.5mm in the clamps, the drawing shows a vertical increase in height at the steering head of 12.4mm.

If I do any changes to the rear height, I'm going to draw a similar diagram, but it will be a little more complicated because the angle of the suspension arch has a similar effect to the rake of the forks in reducing the vertical movement compared to the actual change at the adjusters. Plus, the actual change in height is multiplied by the ratio of the amount of swingarm between the pivot and the arch to the length between the arch and the axle.

Is all this necessary? No, not at all. But I'm curious about things like this. And if I come up with a consistent model that says raising the rear adjusters X amount will equal moving the forks down Y amount, I be sure and share it on the board.
 

·
Premium Member
Joined
·
2,952 Posts
Discussion Starter #10
Chris made a very good point about C of G while I was typing that last reply. That has my interest now, too.

Now I'm interested in riding at Jennings as is. Then raising the rear height and riding again on the same track for comparison.

I figure I'm not a good enough rider to really get much out of top shelf suspension bits like Ohlins - at least until I fully exploit the range of things that can be done with what's on there now. And adjustments are FREE ;D
 
S

·
Guest
Joined
·
0 Posts
well, if anyone is interested, I do have fully adjustable Showas for sale with little miles on them that were just revlaved and serviced (oil, seals, etc.).
 
1 - 11 of 11 Posts
Top